Fear conditioning paradigms are tools to explore symptoms of anxiety disorders. During fear conditioning, the organism develops fear to the phasic explicit cue (e.g., a light) that was associated with the aversive unconditioned stimulus (e.g., a shock) during conditioning as well as to the environmental context (e.g., the experimental room). Explicit cue conditioning and context conditioning are separate processes mediated by distinct brain structures. Whereas explicit cue conditioning is only dependent on the amygdala, context conditioning involves the amygdala, the hippocampus and the bed nucleus of the stria terminalis (BNST). We have been using explicit cue and context conditioning as models of phasic fear and sustained anxiety, respectively. However, contextual fear is relatively difficult to study in humans in the laboratory because it requires two experimental sessions and the use of different experimental rooms. Advances in computer-generated visual stimulation now offer the possibility to develop more sophisticated paradigms in the laboratory that could facilitate the design of fear conditioning studies. In addition, compared to traditional paradigms, computer generated three-dimensional stimulation provides the opportunity to create more realistic virtual environment. The main objective of this study is to use virtual reality to further our understanding of fear conditioning in humans.